A SNOOPING (snooping) or Multicast Listener Discovery Proxy (multicast listener discovery proxy, MLD proxy) technology is generally applied in the process of implementing multicast. When the SNOOPING technology is applied, other network apparatuses above a network apparatus that applies SNOOPING need to perform multicast processing on all received Internet Group Management Protocol (Internet Group Management Protocol, IGMP) packets (such as IGMP join packet and IGMP leave packet). Therefore, a high packet processing capability of the network apparatus is required. When the MLD proxy technology is applied, the MLD proxy terminates the IGMP packet of a User Equipment (user equipment), which does not meet the IGMP packet requirements imposed by the practical network. For example, in the network, statistics collection and analysis for a global user need to be performed according to an on-demand operation from the user equipment. For another example, a network service provider (NSP) needs to provide a transparent channel for an internet service provider (ISP) so that the ISP can obtain the IGMP packet from the user equipment.